Many types of equipment are housed in a chassis, such as computer equipment or other electrical equipment. Frequently a chassis for electrical equipment consists of a base to support electrical circuit boards and other components, with a rigid open framework extending up from the base. The open framework allows convenient access to the electrical components inside, but does not provide a finished appearance or protection of delicate components mounted in the chassis. Exterior panels or other methods of covering the chassis are often required to protect the contents from physical damage and to provide a finished appearance for a consumer or other user.
Furthermore, if the chassis houses electrical equipment, a cover is required to protect users from electrical shock, as bare electrical conductors are nearly always exposed inside electrical equipment. Preferably, a cover for electrical equipment is grounded to increase protection against accidental electrical shock. Electrical equipment can also be sensitive to dust, requiring a cover to reduce the amount of dust reaching the interior of the chassis.
Electrical equipment is often sensitive to radio-frequency (RF) interference, electromagnetic radiation in the various radio frequencies which can disrupt normal electrical operation. A cover for an electrical chassis, if properly designed, shields the chassis from externally generated RF interference. The cover also prevents electromagnetic interference (EMI), electromagnetic radiation generated by the electrical equipment, from leaving the chassis and interfering with nearby equipment. For example, an unshielded chassis housing electrical equipment can cause EMI which would interfere with television and radio reception near the chassis, and with any other systems using radio communication like baby monitors, wireless radio computer networks, or citizens band radios.
A cover also aids in cooling electrical systems. Electrical equipment housed in a chassis must often be cooled by electric fans mounted in the chassis to circulate air over the heat-generating electrical components, cooling them by convection. However, electrical fans are not as effective at cooling electrical components when blowing in large air spaces. A cover can provide a small area through which air is forced, concentrating air flow over the components.
Irregularly shaped chassis can be difficult to cover, requiring multiple panels or mounting brackets, complicating EMI, grounding, and cooling issues, and reducing esthetic appeal. For example, electrical chassis are frequently designed to be mounted in an electrical rack capable of housing multiple chassis. Such rack mount electrical chassis are not designed to be covered simply, since the design considerations for rack mounting and standalone use often conflict. Equipment with a rack mount chassis is often used as a standalone device, but designing and manufacturing two types of chassis can be cost prohibitive. For example, mass storage devices for computers, like autochanger systems, may be used most frequently in a rack to increase storage capacity, but may also be used as a standalone storage device.
A rack mount chassis may have channels in its sides to accept rollers in the racks, allowing the chassis to be retracted from the rack like a drawer. Such rack mounting features like channels present an irregular structure which is difficult to cover. A rack mount chassis also frequently has an oversized face or bezel designed to overlap the edges of the rack and meet with the bezels of the chassis directly above and below. To cover a chassis having an oversized bezel, the chassis must be elevated to prevent damaging the bottom of the bezel, and the chassis must be adapted to meet the top and side edges of the bezel which extend beyond the chassis.
Consequently, a need exists for a cover for a standalone chassis which is adapted to irregular chassis shapes and which is simple and easy to attach, having a small number of components, while providing for EMI and electrical shock protection and being esthetically pleasing. A need further exists for a cover which provides vertical support to a chassis to protect oversized bezels.